A communication throughput prediction device that estimates communication throughput, which is the size (the amount) of data delivered (transmitted) per unit time, is known. As one of this type of communication throughput prediction devices, a communication throughput prediction device described in Patent Document 1 transmits test data having a predetermined data size, and measures a time required for transmission of the test data to be completed. Then, the communication throughput prediction device predicts future communication throughput, based on the measured time.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-037649
Communication throughput in communication using TCP/IP (Transmission Control Protocol/Internet Protocol) relatively largely changes in a short period of time due to complicated action of various factors (e.g., End-to-End delay, packet loss, cross traffic, the intensity of radio waves in radio communication, etc.).
For example, in the communication throughput prediction device, communication throughput may decrease due to increase of cross traffic after transmission of test data is completed, or communication throughput may increase due to increase of the intensity of radio waves in radio communication. In these cases, there is a problem that the communication throughput prediction device cannot estimate communication throughput with high accuracy.